226 Mineralogical Notices. 
In the first of these analyses the magnesia was estimated from 
the loss. 
[The second analysis gives for the oxygen ratio of the pro- 
toxyds, peroxyds, silica and water, 9:51: 10-98: 15-30: 11-17= 
Bie: 12: 9.) 
Byssolite.—Kengott (Min. Unters., i, 77,) has measured the 
capillary crystals of byssolite from the Tyrol, and obtained the 
prismatic angle 124° 21’, which is that of Hornblende. 
Aigirine.—The Agirine analyzed by Plantamour is a Horn- 
blende. Another mineral so called from the Island Skaadén, 
near Brevig, Norway, proves on analysis by Plattner (Pogg., Ixxx, 
315,) to be a pyroxene. According to Breithaupt it is black or 
greenish black to leek green, (the latter when in small crystals,) 
with a greenish-gray streak; cleavage brachydiagonal, perfect, 
macrodiagonal distinct ; parallel to M only in traces. G=3-432— 
3:504. Calculation from a measured angle gives for M: M 86° 
52’, the angle of pyroxene. 
Breislakite——The identity of Breislakite and Augite, has 
been proved by Prof. E. J. Chapman (Phil. Mag., xxxvii, 444, 
Dec., 1850) from a measurement of minute crystals detected by 
him in the Vesuvian specimens. They gave for P on the axis 
106° 18’, M: M=87° 10’. 
Staurotide.—Crystals of Staurotide from Cheronice have afford- 
ed Kenngott (Min. Unters., i, 49) the following angles :—M: M 
( «P)=128° 57’; P(OP):a(P« )=125° 36’; M:a=137° 18’; 
M: e( «Px )=115° 39’. The last angle would give for M: M 
the angle 128° 42’, and for the vertical and horizontal axes the 
relation 0°676 : 1: 0-480. 
Chiastolite—A rhombic prism of chiastolite of a peach blos- 
som color, affording the angle 93° 30’ and specific gravity 3°10, 
gave E. Renou (Expl. Sci. de l’Algérie, Paris, 1848, 58, and Lieb. 
and K. Jahresb., 1849, 736) the following composition : 
Si 366 Al 61: 
with a trace of magnesia and iron, which is the composition of 
Kyanite. It is from mica slate in the vicinity of Bona. 
Garnet.—A columbine-red garnet from Albernreit near Wald- 
sassen in Bavaria, afforded A. Besnard (Correspondenzbl. Regens- 
burg, 1849, iii, 30, Lieb. and K. Jahresb., 1849, 745)— 
Si a1 Fe Yin Lg 
38-76 21-00 82-05 6-43 3°95—=102°19 -—G—=42 
Feldspar of the porphyry of Lessines and Quenast, Belgium: 
by A. Detesse, (Bull. Soc. Geol. de France, [2], vii, 310. )—The 
feldspar is in macled crystals belonging to the triclinic system; 
they are finely striated, of a white color or slightly greenish, Wl 
